Tuber Type Research Articles

A comparison of microtubers and field-grown tubers of potato ( Solanum tuberosum L.) for hexoses, sucrose and their ratios following postharvest cold storage

Cold-induced sweetening (CIS) is a significant postharvest problem in processing potato ( Solanum tuberosum L.) tubers. A rise in hexose sugar levels during cold storage results in a brown, bitter tasting and unmarketable product. We tested if potato microtubers (MicroT) can undergo CIS and if this corresponds to the CIS response in field-grown tubers (FieldT) with the hope of fast-tracking breeding programmes using a MicroT system. Using MicroT from potato genotypes representing a range of CIS response levels we have demonstrated that MicroT undergo CIS more rapidly than FieldT. Correlations of glucose:sucrose and hexose:sucrose ratios were highly significant between the two tuber types after cold treatment and these ratios are known to be good predictors of invertase activity, a key regulator of CIS. Correlations of individual sugars were non-significant before and after postharvest cold treatment.

Multiple-site identification of potato parent clones conferring high levels of late blight resistance with a corresponding genetic model for resistance

Toluca Valley, Mexico, is the putative center of origin and diversity forPhytophthora infestans (Mont.) de Bary, the oomycete pathogen responsible for late blight, making it an ideal location for screening potato breeding populations for late blight resistance. Approximately 21,500 progeny from the USDA-ARS, Aberdeen, Idaho potato breeding program were evaluated from 1996 through 2005 by estimating the percentage of defoliation due to late blight throughout the growing season. Comparisons of the number of resistant progeny and their degree of resistance response from resistant x susceptible (RxS) and resistant x resistant (RxR) crosses were made across years. A clone of each progeny planted in Toluca Valley was also planted the same year near Aberdeen, Idaho, to screen for acceptable tuber type. Promising progeny phenotypes were then screened the following year for tuber late blight resistance at field plots near Corvallis, Oregon. The RxR late blight crosses produced 64% resistant progeny compared to 29% of the RxS crosses. The segregation for late blight resistance in progeny from specific RxS crosses best fits a 1R:3S ratio. This segregation ratio is best explained by a gene model in which resistance is conferred by the presence of a dominant allele at each of two loci. The greater percentage of resistant progeny from RxR crosses indicates the benefits of pyramiding resistance genes from diverse germplasm. Three promising late blight resistant parental clones with acceptable tuber type resulted from family A95053. Family A95053 has multiple sources of resistance that includeSolarium demissum andSolarium stoloniferum, via female parent AWN86514-2 and male parent, B0718-3.

Coloured potatoes (Solanum Tuberosum L.) – Anthocyanin Content and Tuber Quality

Anthocyanins gain more and more importance as natural colourants. Besides many other plant species, coloured potatoes could serve as a potential source. Therefore, 27 potato cultivars and four breeding clones of different origin were analysed for their anthocyanin contents in fresh weight (fw). On average the highest amounts of anthocyanins were found in the skin (0.65 g kg−1 fw) of potatoes. The corresponding values of samples taken from whole tubers (0.31 kg−1 fw) and flesh (0.22 kg−1 fw) were significantly lower (p<0.03). The analysis revealed considerable differences in the amounts of anthocyanins between the 31 cultivars/breeding clones. Among them ȁ8Peru Purpleȁ9 revealed the highest anthocyanin content in the skin with 2.96 g kg−1 fw. A similar high value was reached by ȁ8Violettfleischigeȁ9 and clone 1.81.202–92 N. Also for the other two types of samples, flesh and whole tubers, these three genotypes exhibited the highest level of anthocyanins. Interestingly, different rates of nitrogen fertilization at 100 and 200 kg ha−1 had no significant effect on the pigment content of potatoes. The same was observed with respect to the year or the location of plant growth. There were also no significant changes in the anthocyanin contents of tubers during storage for 135 days. In dry matter, starch and protein contents the coloured potato cultivars/breeding clones were comparable with traditional cultivars. Further tests have shown that the glycoalkaloids were mainly localized in the skin of coloured potatoes.

Ganglioglioma mimicking transmantle focal cortical dysplasia in a two-year old child with intractable epilepsy

We report about a two year old girl with onset of severe temporo-parieto-occipital seizures at age of 7 month, retardation of speech development and ataxia. High resolution T2-weigthed MRI identified a hyperintense lesion arising from the ependyma of the right ventricle to the right superior temporal gyrus. In addition, T1-weighted MRI indicated a slightly hyperintense nodular area within this lesion as well as minute calcification. Neuroradiological inspection was highly compatible with a transmantle type of focal cortical dysplasia or cortical tuber (without further lesions of the tuberous sclerosis complex). PET revealed a hypometabolism of the right parieto-occipital lobe. Maximum valproic acid and oxcarbazepin medication were not sufficient to control seizure activity. Temporo-parietal resection of the lesion was performed and histopathologically examined. In contrast to the clinical diagnosis of a transmantle-type focal cortical dysplasia (FCD type IIB according to Palmini et al., 2004), microscopical inspection revealed a ganglioglioma presenting with dysplastic neurons, a neoplastic glial cell population and expression of CD34– immunoreactive satellite clusters (WHO grade I). Proliferation activity was in the range of 1%. Calcification was present and appeared as microscopically small deposits within small capillaries and neuropil. There were no hint for the presence of balloon cells. Seizure activity is controlled after surgery (postoperative time interval is only 4 month yet). Retrospective analysis of MRI data sets were performed, but gave no further hint for a neoplasia. This is an interesting lesion with histopathological hallmarks of a ganglioglioma (WHO grade I) mimicking a transmantle sign typically observed in FCD type IIB. Indeed, recent molecular-pathological studies point to similar signalling pathways operating in both lesions, i.e. the insulin-growth factor receptor cascade activating the tuberin/hamartin complex.

Study of Shuchi-Bushi, a Powder Type of Aconiti Tuber after being Autoclaved, Especially Concerning Side Effects-Usage and Dosage of Shuchi-Bushi from This Study-

Aconitum carmichaeli debeaux is an essential herbal medicine that possess anti-inflammatory, analgesic, and cardiotonic effects. Five hundred ninety-three subjects were treated with Shuchi-bushi (a powder type of this aconiti tuber that has been autoclaved) added to Kampo extract granules, between the years 1996 and 2002. The patient population consisted of 153 men and 440 women with an average age of 54.5 years. Four patients showed adverse reactions such as hypertension, nausea and hot flashes with Shuchi-bushi. There were no serious adverse effects, and the toxic symptoms disappeared quickly by reducing the Shuchi-bushi dosage, or cessation.Shuchi-bushi has been used in small quantities because of its highly toxic alkaloids. However, this study indicates that Shuchi-bushi can be used more actively.

Pollen morphology of Dioscorea (Dioscoreaceae) and its relation to systematics

This paper adds new data on the pollen and orbicule morphology of 61 Dioscorea L. (Dioscoreaceae) species to the survey of Schols et al. (2001). The results indicate that pollen characters may be significant in infrageneric systematics in Dioscorea. Pollen and orbicule characters are described based on observations with light microscopy, and scanning and transmission electron microscopy, and are critically evaluated and discussed in the context of existing hypotheses of systematic relationships within the genus. Pollen is mostly disulculate (sometimes monosulcate) with a perforate, microreticulate, striate, gemmate, rugulate, or cerebroid perforate sexine. The basal section Stenophora is one of the few sections with monosulcate pollen. Brachyandra, Cardiocapsa, and Seriflorae, three Malagasy sections, are characterized by striate pollen. Pollen morphology strongly supports section Enantiophyllum as a monophyletic group. The correlation between pollen size and tuber type, as suggested previously by P. Su (1987), is confirmed by our data. As found in our earlier survey, orbicules in Dioscorea are mostly spherical with a smooth or spinulose surface. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 143, 375–390.

Effectiveness of selection for quality traits during the early stage in the potato breeding population

AbstractPotato cultivars resistant to cold‐temperature sweetening are of major importance to the processing industry producing both chips (crisps) and French fries. When most modern potato cultivars are maintained in cold storage to retard sprouting, the tubers accumulate reducing sugars, and the products become an unacceptable brown colour when fried. Selection for better processing quality during the early generations of a breeding programme could be of considerable advantage. Using a portable ‘sugarmeter’, which requires only a drop of sap from the tuber on a test strip, many samples can be efficiently surveyed for low sugar as early as the F1 generation. Using seedlings of three test crosses, glucose and specific gravity of field‐grown tubers, minitubers from greenhouses and microtubers from in vitro culture were compared after cold treatment. Although the mean glucose levels of minitubers and microtubers were higher than field‐grown tubers, the correlation between the glucose contents of the three types of tubers was fairly high. A considerable genetic improvement was noted when progenies were grown as minitubers or microtubers, even though the response to selection for low glucose levels in minitubers and microtubers was lower than from direct selection from field‐grown tubers. The specific gravity of field‐grown tubers showed a significant association with freshly harvested minitubers and microtubers. Selection for low glucose content in minitubers can therefore save considerable resources in a breeding programme.

PENGEMBANGAN BIBIT UNGGUL PORANG (Amarphopallus oncophilus) MELALUI TEKNIK KULTUR IN VITRO UNTUK MENDUKUNG KETAHANAN PANGAN NASIONAL

&lt;p&gt;Porang (Amarphophallus. oncophyllus) is a type of plant tubers that have the potential and prospects for development in Indonesia. In addition to readily available, plants are also capable of producing carbohydrates and high harvest index. The last few years a very large porang needs. Porang plant propagation is vegetative and generative in which to make the seeds are ready to harvest takes between 4-6 months. This study aims to determine kinds of the appropriate medium for growing plants porang network and determine the concentration of each medium, so we get a superior porang plants. Research using factorial completely randomized design. The first factor is a growth regulator BAP concentration: 0 mg / l, 0.5 mg / l, 1.0 mg / l, 1.5 mg / l and 2.0 mg / l, while the second factor is the concentration of IBA 0 mg / l, 0.5 mg / l and 1.0 mg / l, in order to obtain 15 treatments and each treatment made 15 replications. Data were collected for the pengkalusan, contamination callus, callus mortality rate, number of buds, leaf buds height, number of leaves and root. The results showed that the addition of plant growth regulators (hormones) BAP in MS medium effect on the number of shoots, buds and the high number of young leaves. The addition of hormone IBA in MS medium pengkalusan affect the process and the number of roots. The addition of hormone BAP and IBA on MS medium did not significantly affect mortality contamination callus and callus. The interaction between BAP and IBA hormone given on MS medium did not significantly affect the pengkalusan, contamination callus, callus mortality rate, number of buds, leaf buds height, number of leaves and root&lt;/p&gt; &lt;p&gt; &lt;/p&gt;

カラーにおける自然分球および塊茎分割による増殖

The natural increases of new tubers were investigated in eight cultivars of Zantedescia. Variental difference in the number of new tubers was observed and eight cultivars were divided into three types of 1-2, 3-4 and 5-6 daughter tubers.Tubers of 'Salfatare' in 1-2 daughter tuber type and 'Carmine Red' in 3-4 daughter tuber type were propagated by artificial division. The largest number of daughter tubers was produced, when mother tubers were divided into 6 pieces in 'Carmine Red', 10 pieces in 'Salfatare' The rates of propagation by artificial division were 1. 7 and 3. 6 times as large as that by natural division in 'Carmine Red' and 'Salfatare', respectively.

ELectroreception In Gymnotus Carapo: Pre-Receptor Processing And The Distribution Of Electroreceptor Types

This paper describes the peripheral mechanisms involved in signal processing of self- and conspecific-generated electric fields by the electric fish Gymnotus carapo. The distribution of the different types of tuberous electroreceptor and the occurrence of particular electric field patterns close to the body of the fish were studied. The density of tuberous electroreceptors was found to be maximal on the jaw (foveal region) and very high on the dorsal region of the snout (parafoveal region), decaying caudally. Tuberous type II electroreceptors were much more abundant than type I electroreceptors. Type I electroreceptors occurred exclusively on the head and rostral trunk regions, while type II electroreceptors were found along as much as 90 % of the fish. Electrophysiological data indicated that conspecific- and self-generated electric currents are 'funnelled' by the high conductivity and geometry of the body of the fish. These currents are concentrated at the peri-oral zone, where most electroreceptors are located. Moreover, within this region, field vector directions were collimated, constituting the most efficient stimulus for electroreceptors. It can be concluded that the passive properties of the fish tissue represent a pre-receptor device that enhances exafferent and reafferent electrical signals at the fovea-parafoveal region.

Pigmentary disorders: update on neurofibromatosis-1 and tuberous sclerosis.

Pigmentary disorders are a common finding in primary care pediatric practice. Tuberous sclerosis and neurofibromatosis type 1 are two pigmentary disorders that have had many changes in their diagnostic and therapeutic approach. This review focuses on the significant advances in the past few years in the genetics and diagnostic criteria of these disorders. A review of the clinical presentation of neurofibromatosis is provided along with the revised diagnostic criteria for tuberous sclerosis. A logical approach to testing the tuberous sclerosis patient and his or her family is included.

Phylogenetic resolution within the tribe Episcieae (Gesneriaceae): congruence of ITS and NDHF sequences from parsimony and maximum‐likelihood analyses

Generic relationships within Episcieae were assessed using ITS and ndhF sequences. Previous analyses of this tribe have focussed only on ndhF data and have excluded two genera, Rhoogeton and Oerstedina, which are included in this analysis. Data were analyzed using both parsimony and maximum-likelihood methods. Results from partition homogeneity tests imply that the two data sets are significantly incongruent, but when Rhoogeton is removed from the analysis, the data sets are not significantly different. The combined data sets reveal greater strength of relationships within the tribe with the exception of the position of Rhoogeton. Poorly or unresolved relationships based exclusively on ndhF data are more fully resolved with ITS data. These resolved clades include the monophyly of the genera Columnea and Paradrymonia and the sister-group relationship of Nematanthus and Codonanthe. A closer affinity between Neomortonia nummularia and N. rosea than has previously been seen is apparent from these data, although these two species are not monophyletic in any tree. Lastly, Capanea appears to be a member of Gloxinieae, although C. grandiflora remains within Episcieae. Evolution of fruit type, epiphytic habit, and presence of tubers is re-examined with the new data presented here.

A classification system for impact-related defects in potato tubers

The type of tuber bruise that occurs for a given severity of impact indicates the condition of that tuber in relation to its impact sensitivity. This article describes a system for classifying such bruises. Such information is important because sensitive tubers can be re-conditioned (e.g., temperature and/or hydration can be adjusted) to reduce risk of bruising during harvesting and handling. Each class of bruise is described, illustrated, and related to tuber condition. The literature review illustrates the inadequacies of previous bruise evaluation systems in relating bruise type to tuber condition. Growers, processors, storage operators and fresh packers can use this system to make informed decisions on adjusting modifiable factors such as temperature, hydration level, and impact velocity to reduce impact-related defects during harvesting and handling of potatoes.

Pathogen resistance in aerial tubers of potato cultivars

Increases in resistance of aerial tubers (cultivars Désirée, Epicure and King Edward) against nine pathogenic potato fungi were determined in vitro using freeze‐dried powder derived from subterranean and aerial tubers as a culture medium, and in vivo by inoculating both tuber types with the storage pathogens Fusarium sulphureum,F. solani var. coeruleum,Phoma exigua var. foveata and Polyscytalum pustulans. Significantly reduced growth rates and spore and conidiophore numbers were recorded when pathogens were cultured on freeze‐dried powder derived from aerial tubers. No effects on spore size of F. solani var. coeruleum were recorded but spore and conidiophore lengths of remaining pathogens were reduced and width increased, except for Colletotrichum coccodes, where the diameter of acervuli increased, and P. exigua var. foveata, where spore length and width were reduced. Reduced disease incidence, severity and spore numbers were recorded on aerial compared with subterranean tubers inoculated in vivo with the four storage pathogens. Spore length of P. pustulans was reduced and spore width increased, while spore length and width of P. exigua var. foveata were reduced on aerial compared with subterranean tubers inoculated with these pathogens. No effects on spore size of Fusarium spp. were recorded. Concentrations of glycoalkaloids, chlorogenic acid, calcium and magnesium were higher in aerial than in subterranean tuber tissue, which may have contributed to increased resistance and effects on size and morphology of fungal spores. The implications of using aerial tubers as an alternative technique for the production of seed potatoes and their importance to the potato industry are discussed.

Density and viscosity of cold flour pastes of cassava ( Manihot esculenta Grantz), sweet potato ( Ipomoea batatas L. Lam) and white yam ( Dioscorea rotundata Poir) tubers as affected by concentration and particle size

The effect of tuber type, paste concentration and flour particle size on the density and viscosity of cold pastes were investigated. The first set of samples were pastes of 5%–50% (w/w, db) of 180 μm flour particles. The second were 10% (w/w, db) pastes of varying size (75–500 μm) of flour particles. Results showed that both the density and viscosity of sweet potato (SP) were highest and significantly different ( P<0.05) from those of cassava (CS) and white yam (WY). The density and viscosity correlated directly ( r>0.95) and significantly ( P r <0.005) with concentration and inversely ( r<−0.75) and significantly ( P r ≥0.005) with particle size. Analysis of variance (ANOVA) indicated that the influence of tuber type was significant ( P<0.01). The density and viscosity for the 40% paste were not significantly different from those of 35% and 45% pastes ( P<0.05). The viscosity and density of the 75 μm sample were significantly higher than those of any sample with larger particle size. These observations showed that tuber type, concentration and particle size are all crucial factors determining the density and viscosity of tuber flour pastes. The experiment has shown that when high concentrations of SP flour with ≤180 μm particle size are incorporated in foods, large changes in viscosity and density would be obtained.

Comparative composition of aerial and subterranean potato tubers (Solanum tuberosum L)

The composition of aerial and subterranean tubers of two potato genotypes cvs Desiree (red skin) and Epicure (white skin) was compared immediately after harvest using a range of analytical methods. Irrespective of genotype, aspartic acid, arginine, glycine, glutamic acid, histidine, leucine, serine, threonine and total amino acid concentrations were significantly higher (P<0·05) in aerial compared with subterranean tuber tissue. Significant increases (P<0·05) in valine in aerial tubers, but no significant differences in alanine, tyrosine and iso-leucine, when compared with subterranean tubers of cv Desiree, were found. In cv Epicure, alanine, tyrosine and iso-leucine were significantly higher in aerial tubers (P<0·05); however, no significant differences in valine were recorded. There was no significant increases in lysine and phenylalanine between tuber types. Regardless of genotype α-solanine, α-chaconine, chlorogenic acid, chlorophyll and crude protein concentrations were significantly higher in aerial tubers compared with subterranean ones (P<0·01). No significant increases in total lipids between tuber types were found. In cv Desiree, ascorbic acid content was not significantly different between aerial and subterranean tuber tissue, but in cv Epicure concentrations were significantly higher (P<0·01) in aerial tubers. Starch concentrations were significantly higher in subterranean tubers of both cultivars (P<0·05). Sugar content was significantly higher in aerial tubers of cv Epicure (P<0·01), but not significantly different between aerial and subterranean tubers of cv Desiree. Regardless of genotype, phosphorus, magnesium, potassium, zinc, manganese and sodium concentrations were significantly higher (P<0·05) in aerial tubers. Iron and copper concentrations were significantly higher in aerial tubers of cv Desiree (P<0·01), but significantly less in cv Epicure compared with subterranean tubers (P<0·01, P<0·05). Calcium concentrations were not significantly different between aerial and subterranean tubers of cv Desiree, but significantly higher in aerial tuber tissue of cv Epicure (P<0·01). Total gross energy (mJ kg−1 FW) was higher in aerial tubers of cv Desiree compared with subterranean tubers (P>0·05), but not significantly different between aerial and subterranean tubers of cv Epicure. The potential applications of aerial tubers for industrial purposes are discussed. © 1997 SCI.

Assessment of PCR-based simple sequence repeats to fingerprint North American potato cultivars

Seven primer pairs flanking di- and tri-nucleotide repeat sequences, identified from previously sequenced regions of the potato genome, were examined for their potential use in DNA-fingerprinting of thirty-nineSolanum tuberosum subsp. tuberosum cultivars (released between 1861 and 1988) and one diploidS. phureja breeding line. Of the simple sequence repeats (SSRs), the primers for six SSRs amplified DNA sequences within the potato genome between cultivars for a total of 14 bands. The polymerase chain reaction (PCR)based amplification products generated from each primer pair consisted of 1 to 2 bands per cultivar but band variation among cultivars demonstrated up to 4 bands per SSR. A similarity matrix generated from five SSRs was able to distinguish 24 of the 40 cultivars. However, when the potato cultivars were grouped by tuber type (round white-skinned, long white-skinned, russetskinned, red-skinned, and yellow flesh) only five pairs of cultivars remained indistinguishable: Atlantic/Katahdin, Belchip/Wauseon, Red LaSoda/Bliss Triumph, Red Pontiac/Norland, and Burbank/Spunta. Although SSRs did not generate unique fingerprints for all of the North American genotypes examined, the potential to discriminate most cultivars should increase as additional SSRs are identified in potato.

Assessment of Potato Breeding Progress in the USA over the Last Century

Potato (Solanum tuberosum subsp. tuberosum) production has increased six‐fold (per unit area) in the USA since the 1920s. Direct comparison of potato cultivars released during the past century can help us understand how potato breeding has contributed to these production improvements and to other important traits associated with marketing and utilization. Our objective was to study trends in potato genetic improvement during four subjective breeding periods (BP) (pre‐1900 = BP I; 1930 to 1949 = BP II; 1950 to 1969 = BP III; 1970 to present = BP IV), and also to compare performance between and within the three major cultivar types (round‐white, long, and red‐skinned). In field trials conducted from 1990 to 1992, under best management practices (with scheduled irrigation) in Michigan, the greatest total yield potential was observed in several cultivars released during BP I and II. These cultivars also had late vine maturities. On average, BP II had the greatest marketable yield. Cultivars released in BP III had the lowest total yield, earliest vine maturity, highest scab resistance and most favorable tuber appearance. General trends over periods were for earlier maturity and improved tuber appearance. Round‐white cultivars improved for chip‐processing ability and dry matter content over breeding periods, while long types increased in percent marketable yield only in BP IV. No trends were observed for scab resistance. When cultivars were grouped according to tuber type, there were no differences in total yield; however, the long types had the lowest marketable yield and the red‐skinned types had lowest dry matter content.

Using Polymerase Chain Reaction-based DNA Amplification to Fingerprint North American Potato Cultivars

DNA from 46 North American potato (Solanum tuberosum L.) cultivars was examined using the polymerase chain reaction (PCR) with 16 arbitrary primers of 10 nucleotide length (10 mers) to determine the efficiency of randomly amplified polymorphic DNA (RAPD) in delineating cultivars, both sexually derived and clonal variants. The 16 primers yielded 43 useful polymorphisms that were evaluated according to the presence or absence of fragments of equal size. All cultivars were discriminated with as few as 10 primers. The russet sport of Burbank was distinguished from a white-skinned clone by one band. More primers (29) were examined to identify a band polymorphism among six Russet Burbank clonal variants. When the cultivars were grouped by tuber type (excluding the russet clonal variants), three to four primers discriminated these commonly grown cultivars. Determination of cultivar integrity was accomplished with PCR amplification, regardless of tissue source (leaf vs. tuber) for DNA extraction. Cluster analysis based on RAPD markers was performed to examine pedigree relationships of the cultivars. Genetic relationships correlated with some pedigrees; however, many exceptions were noted.

Sensitivity to Thiabendazole inFusariumSpecies Associated with Dry Rot of Potato

Fusarium species associated with dry rot of potato tubers during 1992 and 1993 were characterized. We isolated fungi from wounds or preexisting lesions on randomly collected samples of seed, tablestock, and processing tubers, primarily from the northeastern United States. Of 154 samples, 99 yielded one or more Fusarium isolates, 98% of which were pathogenic on potato tubers. The most frequently recovered pathogenic species were F. sambucinum, F. solani, and F. oxysporum, but pathogenic isolates of F. acuminatum, F. avenaceum, F. crookwellense, F. culmorum, and F. equiseti also were isolated. Using logistic regression analysis, significant relationships were found between the Fusarium species isolated and factors such as tuber use, method of isolation, year of isolation, and state of origin of the sample. Of the 200 Fusarium isolates, 82 grew at ≥5 mg/liter of thiabendazole (TBZ) in V8 agar and were considered resistant to TBZ. These included isolates of F. sambucinum, F. solani, F. oxysporum, F. acuminatum, and F. culmorum. TBZ-resistant isolates were obtained from most locations and all tuber types. The effective dose for 50% reduction in growth differed among isolates of F. sambucinum and F. solani, suggesting that there may be multiple beta-tubulin mutations that confer resistance.